In fast food restaurants it is often necessary to make a large number of sandwiches and the like quickly enough to accommodate a large number of customers during busy intervals and to prepare for anticipated demand. Not only must this operation be accomplished rapidly with relatively untrained help, but also the sandwiches must have a reasonably attractive final appearance and, for economic reasons, material such as catsup and other condiments should not be wasted. In many restaurants today the condiments are dispensed from a squeezable container wherein the amount of material discharged depends upon the duration and vigor of the squeeze applied by the operator. Accordingly, with untrained, partially-trained, or careless help a great deal of condiment can be wasted during any operating period while the sandwiches will still not have an appealing appearance to the customer. Accordingly, there is a need for a condiment dispensing device that will effectively dispense a predetermined amount of condiment and one that is particularly usable in a controlled manner by even inexperienced operators.
In the past, dispensing devices have been disclosed, such as that in U.S. Pat. Nos. 4,032,044 and 4,124,147 wherein flexible diaphragms are used to eject charges of material from a dispensing unit, and that in U.S. Pat. No. 3,203,595 wherein special control means are used to control discharges of two different condiments.